The evolution of human-computer interaction can be classified into four main stages. According to Andries van Dam in Post-WIMP User Interfaces [van Dam 97], respectively in Post-WIMP User Interfaces: the Human Connection [van Dam 2001], the first period reigns during the 1950s to the 1960s. Computers are operated in batch mode, and stacks of punched-cards are fed into card reading devices. The second period is the era of timesharing. It starts in the early 1960s and lasts until the early 1980s. The dominating interaction method is manual command line input on mainframes and minicomputers. In the early 1970s starts the third period that is still going on. Computers are raster-graphics-based networked workstations, microcomputers and PCs. They are equipped with a mouse as a graphical input device (GID). The graphical desktop metaphor with windows, menus and icons is the prevailing paradigm. The forth generation has just begun. Van Dam calls it Post-WIMP. «These don’t use menus, forms, or toolbars, but rely on, for example, gesture and speech recognition for operand and operation specification» [van Dam 97, p. 64]. Raj Reddy coined the term SILK interfaces in 1996. They utilize Speech, Image, and Language understanding, and are driven by Knowledge bases [Ibid., p. 67].

This chapter focuses on the third generation of user interfaces. On graphical user interfaces and their history. At a symposium to honor Doug Engelbart in 1998 Ted Nelson has pointed out that ’GUI’ does not depict one single user interface. He said, «there are so many millions of graphical user interfaces possible and yet we are stuck with one in which we have a single fixed little area called the desktop», The Unfinished Revolution and Xanadu [Nelson 99b, p. 4].

Investigating the history of graphical user interfaces might reveal some insights about original objectives that are forgotten nowadays.

3.1 Historical Overview

Remarkably few books and articles cover the history of graphical user interfaces. Many more are success stories of companies, or biographies of their CEOs. A few salutary exceptions to this are A brief history of human-computer interaction technology by Brad Myers [Myers 98], A History of Modern Computing by Paul Ceruzzi [Ceruzzi 98], Dealers of Lightning – Xerox PARC and the Dawn of the Computer Age by Michael Hiltzig [Hiltzig 99], and Der Computer als Werkzeug und Medium by Michael Friedewald [Friedewald 99]. Many details for the following sections are taken from these resources.

The advent of Apple Macintosh in 1984 has initiated the desktop publishing revolution. Computer based type setting using the paradigm of WYSIWYG – What you see is what you get – and laser printers for high quality paper output made it possible for everyone to create professional looking documents. The Macintosh introduced the mouse as a standard input device to double-click folder and document icons, to arrange windows and to pull down menus.

The entire scenery on screen follows the so-called desktop metaphor. All objects are designed to fit into the virtual world of an office. The desktop world literally covers the engineering aspects of the computer. This is to create a familiar and friendly environment for people who are not experts in computer hardware and operating system design. The user deals with documents instead of files. Directories are called folders and look and behave similar to their physical counterparts. They can be opened and documents can be filed into. And most prominently an icon of a trash can is used to delete objects. Document icons are dragged onto the trash can icon where they stay until the trash gets emptied.

The Macintosh was the first computer with a graphical user interface that was commercially successful. But the development starts long before Apple Computer was even founded. This section presents a trip through the history of the modern user interface for personal computers.

The journey starts in 1960. Joseph Licklider (*1915 †1990) wrote the article Man-Computer Symbiosis [Licklider 60] in which he proposes interactive computing as a new paradigm to make use of the computer. Two years later he became the first director of the Information Processing Techniques Office (IPTO) at ARPA. IPTO’s objective was to devise new utilization of computers other than plain computation. Especially the military was looking for computer systems that support decision processes with short response times. To Licklider this was pretty much the same as his vision of Man-Computer Symbiosis (cf. 3.1.1). During the 1960s IPTO funded several research projects to develop time-sharing computer systems and information processing projects.

MIT Lincoln Laboratory was one of the institutes that was supported for their research work on interactive computer graphics. Ivan Sutherland presented 1963 in his Ph.D. thesis Sketchpad: A Man-Machine Graphical Communication System [Sutherland 63a] a working program to interactively edit vector based illustrations with a light pen directly on screen. Also the concept of a window was first used in Sketchpad (cf. 3.1.2).The user can zoom into a drawing area and all graphical elements are clipped against the edges of the screen. Sutherland’s ground breaking work is the starting signal to develop interactive user interfaces with graphical aspects for the decades to come.

The Augmentation Research Center at Stanford Research Institute (SRI-ARC) has already been mentioned in the previous chapter about hypertext. Now the system NLS (cf. 3.1.3) will be examined from the perspective of interaction techniques. Doug Engelbart’s long term objective is the augmentation of human intellect. His fundamental research lead especially to the invention of the mouse in 1963. Windows, interactive text editing, the five-finger chording keyset input device, and video conferencing are other development projects at SRI.

Xerox Inc. grew by the commercial success of the Xerox copier machines in the 1960s. In 1970 they founded a new research laboratory. The mission for Xerox Palo Alto Research Center (PARC) was to explore the opportunities of new computer systems for office appliance. With this step Xerox tried to be prepared for the dawning age of personal computing. Alan Kay has formulated this idea as, «The best way to predict the future is to invent it» (e.g. in [Frenkel 94, p. 22]).

One of the things that was developed at Xerox PARC was the Laser Printer with the two components Scanning Laser Output Terminal (SLOT) by Gary Starkweather, and the Research Character Generator (RCG) by Butler Lampson and Ron Rider. SLOT is a technique that uses a laser beam to transfer an image to the xerographic drum, while RCG is a way to create a bitmap of text in computer memory.

The Alto computer (cf. 3.1.5) is the ancestor of modern PCs. It was principally designed by Butler Lampson and Chuck Thacker and had a 72 dpi bit-mapped graphic display and a mouse. Ethernet was invented by Bob Metcalf in cooperation with David Boggs, Chuck Thacker, Butler Lampson and others in 1973. This new technology made it possible for PARC to connect all the Altos to the first local area network (LAN).

All these parts together were the ingredients to EARS, which stands for Ethernet-Alto-RCG-SLOT. When EARS became operational in Autumn 1974, the system started immediately to attract people at Xerox PARC. Everyone wanted to have an Alto of her own. The prototype for an office of the next decade was established by the word processing applications program Bravo by Charles Simonyi, the newly developed paradigm of WYSIWYG, and the possibility of printing documents in high quality to the shared SLOT terminal. About 50 units of the Alto I and more than 1,500 units of the Alto II were produced until 1980 [Friedewald 99, p. 275].

The path towards personal computing was not taken by chance. Alan Kay directed the Learning Research Group (LRG) at PARC. His master and doctoral thesis at the University of Utah about the Flex Machine (cf. 3.1.4) became the research program for the group. Many aspects of the Alto computer are directly influenced by Kay’s vision of the Dynabook (cf. 3.1.4), A Personal Computer for Children of all Ages [Kay 72a]. Alan Kay and Adele Goldberg took the Alto computer as an Interim Dynabook into the classroom. The article Personal Dynamic Media [Kay/Goldberg 77] shows that school kids were able to program the computer with the newly developed object-oriented programming language Smalltalk (cf. 3.1.5). The work with children revealed many interesting insights into the field of human-computer interaction.

The Alto had always been an experimental prototype. The project of a commercial system that builds on top of all the research results of PARC started in 1975 and led to the development of the Xerox 8010 Information System. The Xerox Star (cf. 3.1.6), as this system was called for short, was presented in 1981. It introduced a consistent graphical user interface that covers the operational tasks of the computer with the notion of an office environment. The desktop metaphor was born, although it was originally called the physical-office metaphor.

While Xerox PARC is located in California the Architecture Machine Group was working at MIT in Massachusetts. It was formed in 1967 by Nicholas Negroponte and got financial support from the Cybernetics Technology Office (CTO), another division at DARPA.

In the mid-1960s Negroponte was a student of architecture. His dream was to have a machine to support the creative design process of architects. He was convinced, that for such a device to be truly helpful, it would have to be intensely interactive with the human user, The Media Lab: Inventing the Future at M.I.T. [Brand 87, p. 137]. This explains the heritage of the name of the Architecture Machine Group, and also the devotion for human-computer interaction.

Throughout the 1970s, the Architecture Machine Group explored chances of a computer-based medium. The Aspen Movie Map for example is a video disk application, that offers a virtual tour through the city of Aspen, Colorado. The user is free to move in any direction and even to change the season at any point of the session [Nielsen 95, p. 40]. Other projects use speech or holographic images. But especially Richard Bolt’s work on the Spatial Data Management System (cf. 3.1.7) is of interest for the history of graphical user interfaces. One of SDMS’s components is called Dataland. It is the projection of data to a two-dimensional field. The user can move and zoom into the Dataland to enlarge thumbnails of documents until the content becomes accessible.

It is often rumored, that Apple Computer, Inc. took initial inspiration for the Lisa (cf. 3.1.8) and Macintosh (cf. 3.1.9) projects from a visit at Xerox PARC. This visit did actually happen in November 1979, but proposals for Lisa and Macintosh are dated respectively to October 1978, and May of 1979.* *In Holes in History Jef Raskin, head and father of the Macintosh project, passionately argues against such simplified chronicles [Raskin 94a]. Raskin cites an e-mail conversation with Robert Cringely: «“As for all the business of what project started when, whether Lisa started before or after Steve [Jobs, founder of Apple Computer, Inc.] visited PARC, whether the Mac had already begun or not, well I don’t think that it really matters very much. My attempt was to EXPLAIN […], not to be a historian.” How an author can hope to explain what happened if he doesn’t even know what happened eludes me.» [Ibid., p. 15] A demo of Smalltalk was given to Apple’s engineers that consolidated their understanding of a graphical user interface with windows, menus and the mouse as graphical input device. Another important influence for the Lisa team was MIT’s Spacial Data Management System. The way Lisa, and later the Macintosh user interface deal with spacial arrangements of icons has their roots in SDMS Dataland. The Lisa was presented in 1983 but like the Xerox Star before the Lisa was not commercially successful. The interface concepts were too ambitious for the performance for the hardware of that time.

Finally with the Macintosh, Apple managed to offer a system with an intuitive user interface for an acceptable price. Together with the Apple LaserWriter and a built-in network, the Macintosh turned out be extremely popular and commercially successful.

No historical overview can mention all the contributions that led to the graphical human-computer interface that we are all using today. The following sections will present some astonishing concepts and ideas that are in some cases more than 40 years old but not outdated in any respect.

The discussion could have started again with Vannevar Bush. But a cross reference to section 2.1.1 Memex shall do.